Fluid-pressure brake



Dec. 20, 1927.

T. H. THOMAS FLUID PRESSURE BRAKE Filed April 11. 1927 INVENTOR THQMAS H .THOMAS.

BY 41 ATTORNEY hm m6 Patented Dec. 20, 1927.

, PATENT OFFICE.

UNITED STATES V EHOMAS H THOMAS, or nnenwoon, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE AIR BRAKE'COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION PENNSYLVANIA.

FLUID-PRESSURE BRAKE Application filedApril 11,1927. ser al No. 182,744.

a sudden or emergency reductionin brake pipe pressure is initiated somewhere in. the train, other than by theoperation of the automatic brake valve device, this reduction will be propagated serially throughout the train by the Well known quick serial action, and the brakes will be applied.

Under such a condition, if the brake valve device is not moved from the running position to lap position, so as to cut off the flow of fluid to the brake pipe, the brakes on the locomotive and on cars at the head of the train are liable to be released by the continued flow of fluid to the brake pipe.

The principal object of my invention is to provide means for automatically cutting off the flow of fluid to the brake pipe at the brake valve device after an emergency re duction in brake pipe pressure has been produced, thereby preventingan undesired releasing of the brakes. v Another Ob]GCb of the invention Is to provide means whereby an emergency reduction in brake pipe pressure will automatically cause the flow of fluidto the brake pipe to be cut of? and whereby under any service re duction in brake pipe pressure the fliow'ot fluid to the brake pipe will not be cut off.

In the accompanying drawing, the single figure is a diagrammatic sectional view of a brake control equipment, embodying my 1nvention.

The apparatus shown in the'drawing includes a brake valve device 1, a distributing valve device 2. the usual feed valve device 3 and a cut off control valve device 4.

The brake valve device 1 preferably comprises a casing having a valve chamber 5,

containing the usual rotary valve 6 Which is adapted to be operated through the medium oi a handle 7. Included In the casing, is the usual-equalizing discharge valve mechanism comprisinga piston 8, having thechamber 9 at one side thereof connected tothe equaliz 12, and pipe 18. 'At the opposite side of the piston 8'the chamber 14 is connected with the brake pipe 15 through i apassage 16 and branch pipe 17. The piston 8 is adapted to ing reservoir 10 through a passage 11, choke. I

operate a discharge valve 18 forcontrolling the venting of fiuiditrom thebrake pipel5. Also included in the brake valve device casing, is a cut-off valve mechanism comprising a valve '19 contained in a chamber 20 and adapted,-1n one position, to seal against a, seat ring 21. The'valve 19 is connected with the stem 22 of a piston 23, at one side of which piston there is a chamber 24 con nected to the brake pipe 15 through a passage 25, passage 16 and "branch pipe 17. At the opposite side of this piston there is a chamber 26 containing a spring 27 which acts upon the piston. There is also a double beat valve 28 adapted, in one position to.

close communication between chamber 26 and-a passage 29, and in the opposite or normal position, in Which it is held by the pres sure of a springBO containedina chamber 31, to seat soas to prevent leakage from this chamber totheflatmosphere. This valve 28 has an extendedstem provided with an en larged outer end portion, 32 by which the valve is manually operated.

Thedistributing valve device 2 comprises a casing having the usual application portion 33 and equalizing portion34.

The distributing valve application portion 38 comprises a casing having an application cylinder 35 containing an application piston36, avalve chamber 37 separate from the piston'chamber 'at'the right of the application piston 36 by piston 38 and contaimng an exhaust valve 39, and'alsov has a valve chamber 40 containing an application valve 41, both ofsaid valves being operated by theimov'ement of the pistonstem 42.

The equalizing portion 34 of this distribut ing valve device, comprises a casing having a piston chamber 43 containing an equalizing piston 44, and a valve chamber 45 containing a main slide valve 46 and an auxiliary slide valve 47adap'ted tobe operated by said piston. The casing also contains the usual I pressure chamber 48and application CllillYlber 49. Y

The cut-oii' control valve device 4 may comprise a casing having flexible diadiaphragmhl, The chainher 65- is connect phragms and 51 mounted therein, the chamber 52 at one side of the diapln'agi'n 50.

being connected With the application chamher 4-9 of the equalizing portion 3st ofthe distributing valve device, by a pipe 53 and containing a spring 54 which acts upon the diaphragm 50. The chamber 55 at the other side of the diaphragm 50 is connectedwith the brake cylinder 56 and ch ainher SfQotiithe application portion of the distributing valve. device, by a pipe 57,;and contains a, W 815011Controlling a comn'iunication, between the chamher-55 and achamher59 at one sideof the diaphragm 51. Thevalve 58 issecured to the diaphragm 50 and has a fluted "stem GO, past, which, fluid may flow from the" chamber to the chamber ,59, the chamber 59 being open to the atmosphere through a: passage, 61; containing a choke 'plugGQ Thechamher 63, at the other side of the diaphragm 5 1, is open toithe atmos phere through a port 64, and is adapted, to communicate with a chamber 65 in the casing, such,communication being controlled,

by a, valve 66 contained. in the chamber,

65 andvvhich is acted uponhya spring 67 Which tends -to maintain v; the valve closed, This valve lhas ai fluted stem 6S \Vl1lCl1.;iS adapted toengagewiththe under sideof the ed with the cut-otl? valve device of the brake valve device by a pipe 69.,

Assumi the brak ewalve dovice to-he in running "position as shown in the drawing,

and the trainibrakcsreleased, fluidnt the reduced pressure supplied by the feed valve device 3, fiows throughfa pipe 70,, passage 71 in the hrakevalve device, cavity-72 in the rotary valve and then throughspassages 73 and 11 to chamber? at oneside of the equalizing piston and also through, the passage 11, choke 12 meme to,,thc equalizing resertoir 10.; Fluid at feed gnalve pressure also flowvsto valve, chamber 20,1 through the cavity 72in thejrotary valyeli, a portM in thisvalve, and, a passage 7 andalso from passage Tothrougha passage 76 (iOl lhflllllllgil chokeplug 7 into thespring chamber :26 of the cut-off 'valve mechanism, which chamber in turn is connected,-through the passage "29 and pipe i9 with thechan her ot the cut-off control. valve device. In initially charging the brake systen'h,the, spring 6 will hold thepvahxeh$ 0tthecutofi control valye device 4, closed so that fluid supplied to the chamber (35 cannotesf cape to the atmosphere by v-xay'o'f the, Chad]; her and port ea, and valveGG heingheld closed, the fluid pressure in chamber zli is permitted to build up to cqual that incham her 20,which permitsthe spring 27 to shift". and hold the piston 23 and valve 19in the position as shoivn in the drawing. In this position, fiuid at feed valvepressure Will flow from the chamber 2Q to the chamber 24 atmosphere in the release position x of the i fluid under pressure iirtheyalve chamber and .from thencethrough passages 25 and'16 to the brake pipe 15 and1tothe equalizing piston chamber 14 and thus charges the brake pipe and chamher 14:. As the pres sur es on hoth sides of the piston 8 are Tl? equalized, the discharge valve 18 is held seated,

Vith the brake valve device in running position an cl the equalizing portion 34 of the distributing valve device in release position,

the application; cylinder is vented :to the atmosphere through, passages, 7 8 and y 79;. cavity 80 in the equalizing slide valvewlfi passage 81, the usual release ;pipe 82,; passage ,1 83 in the hrakevalve device, andthrpughg l cavity St in the rotary. valve photo the exhaustpassage ,85. When the application, cylinder 35ylS, thus vented, the applicationn pisto n j36, will them the position as shown in. I the drawing and when inthisposition, the ke yl der 5. a d i sor hamber k the cut-off control valve device 4' will he vented to the atmosphere through pipei57', a passage 86 in; the distributing ,valvev device, valve chamber 3l and exhaust passage 87., ChamherhQof the cut olf control valve de vice being connected by pipe 53 to,the, .ap-, plication chamher 49, isialso ventedito the equalizing valve device.

When a sudden or emergency-reductionv in brake pipepressure is initiated Somewhere in the train, said, reduction is propagated serially, throughout the train in the usual Well known manner and when the reduction in pressurereaches thelocomotive, the pressure in the brake pipe 15 and piston, chamber 43 of. thedistributing valve device ,will he, suddenly reduced, causing the equalizing piston, l i to be moved,,by fluid under pressurelin the chan herswla and slhlo its ,emeia gency posit-ion. Movement of the equalizing piston to tl iisposition,shifts the slidevalves 46 and 47 to emergency position in, whicln, 1m

and pressure chan'iher rene s past the endi of the'slideyvalve lhintopassage 79'and then througlrpassage T8 to the pplication cylinv der 35, causing,the application piston 36. to move and shiitjt .the v exhaust. slide valve 39 to a positionflvhere such valve closes the comn'iunicat i on between, the valve chamber 37 and passage 87 to the atmosphere, and also shifts the slide valve 41 to such a position as to open the communication between the valve chamber 37 and the valve chamber 40. The chainber 4-0 being connected by a rpassage 90,and pipe .91 to the mainreservoir (not shown), fluid under pressure from this T reservoir flowsinto valve chamber,e O and then throuq'h valve chamber 25?, passage 86, and pipe 5'1 to the brake ,c ylinde f 50and device 4, and, the brakes will ibe applied. Fluid at brake cylinder pressure is alsosuu plied tothe chamh er 55 and causes the dia;

pressure in this chamber will build up and cause the diaphragm 51 and valve 66 to be moved downwardly, thus opening the communication betweenthe chambers 59 and 65 and permitting the fluid under pressure in the cut'ofl valve piston chamber 26 .to be vented to the atmosphere through the pas-' sage 29, pipe 69, chambers 65 and 63 and port 64. The fluid under pressure in the chamber 26 is vented to the atmosphere at a faster rate than it can be supplied through the choke plug 77, which is interposed be tween this chamber and the feed valve device 8, so thatthe feed valve pressure in chambers and 24'operates to shift the piston 23 and valve 19 against the pressure of the spring 27, until the valve 19 seals against the seat ring 21, thus cutting oil the communication between the chamber 20, which is connected with the feed. valve device 3, and the chamber 24 which is connected with the brake pipe 15, so that even though the brake valve device remains in running position, fluid at feed valve pressure cannot flow to the brake pipe.

To release an application of the brakes, caused as hereinbefore described, and with the brake valve device still inrunning position, the double beat valve is pushed in \vardly, seating the inner valve which closes the communication from thespring chamber 26 to passage 29. Fluid from the feed valve device 3 then flows into this chamber and builds up a pressure suflicient to permit the spring 27 to shift the piston 23 and valve 19 to their open positions, as shown in the drawing, when fluid at feed valve pressure again flows from the chambers 20 and 24 to lVhen the brake pipe pres.)

the brake pipe. 7 sure is sufliciently increased, the equalizing piston 44 and slide valves 46 and 47are shifted to release position, in which position the brakes will be released in the usual H1311, ner. It will, however, be noted from the foregoing description that when the application piston 36 is in its release position, the

fluid under pressure in the chamber and brake cylinder 56 is vented to the atmosphere, thus permitting the spring 54, which has been compressed, to move the diaphragm 50, of the cut-oil control valve device 4,

downwardly, seating the valve 58' which closes the communication between the chainbore 55 and V Fluid under pressure in the. chamber will new exhaust to the atinos-,

pliere through the passage 61 and choke plug (32, permitting the diaphragm to return to its normal position, as shown in the drawing, which in turn permits the spring 67, which has been compressed, to seat the valve 1 claim as new and desire to .66 thus closin the communication between the chambers 63 and 65 and preventing fluid under feed valve pressure in the chamber 26 from being vented through these chambers to the atmosphere.v

lVhen the brake, valveG is moved tolservice position, the brake pipe 15 and piston chamber 43 will be vented to the atmosphere in the usual manner, causing; the piston 44 and slide valves 46 and 47 to move to their service positions, in which, fluid under pressure from the pressure chamber 48 in the distributing valve device and valve chamber 45 will flow through a passage 89 in the slide valve 46 and passage 78 to the application piston cylinder 35 and the application cham- 3 her 49 and will also flow from the application chamber 49.,- through pipe 53 to the chamber 52 in the cut-off valve control device 4, thus the pressure in the chamber 52 will be maintainedequal to the pressure in the applicationchamber 49 so that, when the application portion of the distributing valve device is in service position, the brake cylinder pres.- sure in the chamber 55 of the cut-off valve control device will not cause the diaphragm to move uuwardl i and unseat the valve i i It will thus be seen that, when a service application of the'brakes is eflected, the cut-oil valve mechanism will notibe permitted to operate to cut oil the supplyof fluid pres sure tosaid brake pipe, nor will it be permitted vto operate even when a service overreduction in brake pipe pressure is eflected.

Having now described my invention, what secure by Letters Patent, -is: I '1 I 1. In a fluid pressure brake, the combina tion with a brakev pipeand a brake valve device having means for supplying fluid under pressure to the brake pipe, of a dis- 4 tributing valve devicehaving an application chainber,.and means controlled by fluid under pressure in said chamber and operated only upon an emergency reduction in brake pipe pressure for cutting oit the supply of fluid under pressure from said brake valve f device to said brake pipe.

2. In a fluid pressure brake, the conibina-' tion with a brake pipe-and a brake valve device having a position in which fluid under )ressure is llOllnlll sujalied to the brake pipe to maintain thepressure in the brake pipe at a predeternnned degree, of a distributing Valve device having an applica- 1 tion chamber, and means subject to theprcsa sure in the application chamber and operated only upon an emergency reductionin brake pipe pressure for cutting off the sup-- ply of fluid through said brake valve device to the brake pipe.

3. In a fluid pressure brake, the combination with a brake pipe and a brake valve device having means for supplying fluid under pressure to the brake pipe, of a brake cylinder,andinieans operable .by fluid under brake cylinder prcssure,upon an emergency device having a runningposition in whichcommunication established for supplying lluid under pressure the brake pipe, of means operated upon an emergency reductionnin brake pi 'ie pressure for closing said communication, and means forrendering the firstinentioned means inoperative when a service reduction in-brake pipejpressure is effected;

Ina fluid pressure brake, the combinationwith a I devicefor supplying fluid under pressure to the brake pipe, ol 'a cut-oil valve device for controlling the commun i cation to the brake pipe a control valve device op= erable upon an emergencyreduction in brake pipe pressure for causing said cut-off valve device, to close i said cmnniunicatioin and means including awlistributinp; valve device whereby said cut-oil valve dc ice and control valve device-are rendered inoperative when a Service rcductioinin brake pipe pressure is effected.

6. In a fluidpressurebrake, the combinationwith a brake pipe and a feed valve devicefor supplying fluid under-pressure to adapted to control said cut-ottvalve device for closin said communication and a dis- 5 I tributin valve. device 0 )erable u )OIL I an s l l emergency reduction-1n brake pipe'pressure operableupon a ser-vicereduction inbrake pipe pressure for rendering said control.

valve :device inoperative.

7. In a fluid pressure brake, thecoinbination with a brake pipe and a feed valve-device fox-supplying fluid umlenpressure to-- the brake pipe. of a cut-ol'l'valve device for the coininunicatuinr through controlling which said feed valve device supplies fluid to lhebrake pipe a distributinavalve device having an applicationporrion and an equalizing portion, a control valve device adapted to operate to control the-closing of said cutoff valve device. means insaid distributing valve device operable upon aneniergency reduction in brake-pipe pressure to supply fluid under pressure ironr said application portion to said control valve device for opcrating said control valve device.

8. In a fluid pressure brake. the combination with a brake pipe and a feed valve device tor-supplying fluid under pressure .-to

brake pipe anda feed valve pipeanda 'feed valvedevice -for supplying; through which said feedvalve device SlipPllGsllUUil A cut-oii control valve device; a'distribut-ing and a feed valve device -for supplying -fluid the. brake pipe of a cut-oil valve deviceim" controlling the communication' through which said feed'valve device' supplies fluid to the brake pipe, a distributing valve "device having an application portion and an equalizing portion, a control valve device adapted to operate to control theclosing of said cut-ofi' valve device, meansin said distributingvalve device operable upon an emergency reduction'in brake pipe pressure to supply fluid underpressure from said application portion to said control'valve device for operating said control valve device, and; means associated I with said equalizing poition operableupona service reduction in' brake pipe pres-e re for rendering sai'd con trol valve inoperative i 9. In a fluidpressure brake thecombination I with a brake pipepa brake cylinder l'luidunder pressure to the'brake'pipe, of a cut-(iii valve 'devi'e forcontrollingccominunication through which said-feed valvedevice supplies fluid to said brake pipe; a

valve device. and means-included in-said distributing valve device operable upon an emergency reduction'in brake-pipe pressure for causing fluid under brake cylinder pres sure to be supplied to-=said-cutofi' control valve device to operate-it toicontrol said butoil valve device.-

10. In fluid pressure-brake; the'combina tion with a brake'pipe a brake cylinder pipe under pressure to'uthe brake pipe; of a cutoil valve device for controlling 'conimunica-z tion through which said -feed valve device. supplies fluid. to said brake pipe, a cutoffcontrol valve device, a distributing valve device.- means included in said distributing valve device operable upon an emergency for causing thecontrol valve tooperate, and

' and afeed valve device for 'siuiplying fluid under pressure to the brake pipe, of a. cut

olt valvedevice for controlling communicm tionthrough which said feedvalvc device supplies-fluid to-said brake pipe, a cut-off control valve deviceya distributing valve' device, means included in said d stributing valve device operable upon an emergency reduction in brake pipe pressure for causing fluid under brake cylinder pressure to be supplied to saidcut-olt controlivalve device, and means in said cut-off control valve device operableby thefluid under-brake cylinder pressure for" causing said cut-011 so a valve to voperate to close said communication, said distributing valve means when operated by a service reduction in brake pipe pressure being adapted to maintain said cut-ofl control valve inoperative.

12. In a fluid pressure brake, the combine tion With a brake pipe and a brake valve device having a position in which fluid under pressure is normally supplied to the brake pipe, of a cutofl valve device for controlling communication through which fluid is supplied from said brake valve de vice to the brake pipe, an equalizing slide valve device operated upon a reduction in brake pipe pressure foreliecting an application of the brakes, and means controlled by said equalizingslide valve device for effecting the operation of said cut-01f valve device to close said communication, only when an emergency reduction in brake pipe pressure is eflfected.

13. In a fluid pressure brake, the combination with a brake pipe and a brake valve device having a position in which fluid under, pressure is normally supplied to the brake pipe, of a valve for controlling communication through Which said brake valve device supplies fluid to the brake pipe, a piston operated by a variation in fluid uner pressure for operating said valve, a distributing valve device, and means controlled by said distributing valve upon an emergency reduction in brake pipe pressure only, for varying the fluid under pressure on said piston.

14. In a fluid pressure brake, the combination with a brake pipe and a brake valve device having means for supplying fluid under pressure to the brake pipe, a valve device for cutting off the supply of fluid under pressure from said brake valve to said brake pipe, a distributing valve device, a control valve device having a valve therein operable by fluid under pressure from said distributing valve device upon an emergency reduction inhralte pipe pressure for closing the cut-off valve device. a

15. In a fluid pressure brake, the combination with a brake cylinder, a brake pipe and a brake valve device having means for supplying fluid. under pressure to the brake pipe, of valve means for controlling com munication through which fluid is'supplied' to the brake pipe by said brake valve device, a valve device having an application chainber, means operated by an increase in pressure in said chamber for effecting an application of the brakes, and a valve device subject to the opposing pressures of the brake cylinder and the application chamber for controlling the operation of said valve means.

16. In a fluid pressure brake, thecombination with a brake cylinder, a brake pipe and a brake valve device having means for supplying fluid under pressure to the brake pipe, of valve means for controlling communication through which fluid is supplied to the brake pipe by said brake valve device, a valve device having anapplication chamber, a distributing valve device having an application chamber, and means subject to the opposing pressures of the brake cylinder and said application chamber for'controlling the operation of said valve means.

In testimony whereof I have hereunto set my hand. i

THOMAS H. THOMAS. 

